Chelsea's caretaker manager, Guus Hiddink, could quit Russia if he fails to qualify for the World Cup. Photograph: Shaun Botterill/Getty Images

The possibility of Guus Hiddink being in charge at Chelsea in the long-term resurfaced yesterday when the Dutchman revealed that he has a clause in his contract with the Russian Football Union that means he could be released from his duties with the national team if he fails to secure qualification for the 2010 World Cup finals.

Hiddink has won six of his seven matches in charge since taking over from Luiz Felipe Scolari last month, with the four successive victories in the league lifting Chelsea from fourth to second and renewing talk of a title challenge. He is due to leave Stamford Bridge at the end of the season, something which he has maintained that he will do on several occasions, yet speculation continues to mount that he may decide to swap Moscow for London permanently.

Earlier this week Valery Gazzayev, the former CSKA Moscow manager, announced that he was keen to take over as the national team coach for a second time and, according to Hiddink, that opportunity would become available if Russia, who are currently second in Group Four behind Germany, falter in their qualifying campaign for South Africa.

"I will focus on Russia after this project but people say, 'Think about it, stay'," said Hiddink, alluding to the calls for him to remain at Chelsea beyond the end of the season.

"I enjoy it with the Russians but I do have a clause that says we can stop in November if Russia don't qualify. Then, the Russian FA can choose another direction and I would also be free to go."

Meanwhile, Michael Essien has revealed his delight at returning to the Chelsea side and scoring against Juventus in the Champions League after a six-month absence with a knee ligament injury.

"It was great to be back and scoring," he said. "It had been a very long injury and in the end I managed to come back. The physios and doctors did a great job on me and the first thing that came into my mind when I scored was to go to ­Thierry [Laurent, Chelsea's rehabilitation physio] as he has been with me for the past six months.

"He was the one who was with me every day so I tried to go to hug him and say thank you."